From the whopping magnetic fields surrounding neutron stars to the feeble crustal fields of Mars, magnetized bodies and their magnetospheres are present throughout the universe. Although the outer boundary, or the magnetopause, often shields the magnetized body from the surrounding space environment, energy can sometimes pass through and cause significant disturbances. At the Earth, the understanding developed over the past several decades is that the energy coupled in from the flowing solar wind is purely a function of the conditions within the solar wind. In contrast to this, I will present new spacecraft observations from the THEMIS mission as well as ground-based measurements suggesting the magnetosphere, with the help of a plasmaspheric plume, is defending itself from intense solar activity. In this framework, the internal conditions within a magnetosphere can impact and even control how energy is coupled in from the outside environment.

The space environment provides a near-pristine laboratory for studying plasma physics. /In situ/ particle instrumentation complemented by electromagnetic fields can be used to study plasma dynamics at all scales, ranging from astronomical units to individual particle motion. In addition to scientific expertise, detailed technical knowledge of instrument design and behavior is paramount for finding signal in the noise and maximizing the scientific return of space missions. Here, recent data from the MESSENGER spacecraft is used to demonstrate how penetrating radiation that inhibits nominal plasma measurements can be used to infer magnetic topology and remotely probe the smallest scales in Mercury’s space environment.Such structure will be measured in great detail at Earth with the Fast Plasma Investigation suite on the upcoming Magnetospheric Multiscale Mission (MMS). Key engineering innovations in both laboratory and in-flight calibration activities will be presented that will enable MMS to provide the highest ever spatial and temporal resolution measurements of space plasmas.

Subject: Exploring the Sun at high energies: progress and new instrumentation

The Sun provides a nearby case study in which to study plasma processes and high-energy astrophysical phenomena with high-resolution remote sensing combined with in-situ data and even multiviewpoint measurements — tools that are not available to study any object outside the solar system. In addition to basic physics research interests, understanding high-energy aspects of the Sun also has practical applications, since Earth-directed solar eruptive events can pose a danger to satellites, astronauts, and power grids. New, direct-focusing techniques are now available to study solar flares and eruptions using hard X-rays. The first generation of solar-dedicated hard X-ray focusing optics has recently flown on suborbital missions (rockets and balloons). And from low-Earth orbit, the Nuclear Spectroscopic Array (NuSTAR), a direct-focusing instrument designed to look at the faintest objects outside the solar system, has also produced detailed hard X-ray images of the Sun. This seminar will cover recent advances in high-energy solar flare physics and will present new instrumentation, with emphasis on NuSTAR solar observations and on the FOXSI solar sounding rocket.

Subject: Measuring electrons in the solar wind: current status and future missions

Electrons are critical to the thermodynamics of the solar wind plasma. Due to their high mobility, they carry the majority of the heat flux in the solar wind. Electron beams can also be used as remote probes of the physics of shocks and solar flares. However, making accurate electron measurements is difficult: electrons are susceptible to spacecraft charging effects, and the non-thermal character of the electron distribution function limits the utility of plasma moment calculations. In this talk, I will present recent advances in precision measurements of solar wind electrons, and discuss their application to solar wind thermodynamics, shock acceleration of electrons, and electron heating associated with solar wind reconnection events. I will also discuss the measurement of electrons with particle and electric field instrumentation on the upcoming Solar Probe Plus mission.

Subject: Investigating the dynamics of Earth’s radiation belts through new CubeSat measurements and conjunction studies

The Van Allen radiation belts, composed of energetic ions and electrons trapped around the Earth, often exhibit dramatic variations in intensity and spatial extent. Characterization of the processes contributing to electron acceleration and loss in this region is critical to understanding the variable near-Earth space environment. Here, we’ll investigate the contribution of electron precipitation into the atmosphere to radiation belt dynamics and losses. Through a combination of long-term existing data sets as well as recent CubeSat and balloon measurements, we exploring the nature and extent of electron loss to the atmosphere as well as what electromagnetic wave modes may be causing it. These studies aid in the understanding of outer radiation belt dynamics and the relationship between precipitating energetic electrons, electromagnetic waves, and global magnetospheric conditions. They also demonstrate how small inexpensive CubeSats can complement larger missions and significantly enhance their scientific return.

The Earth is bathed in the atmosphere of our nearest stellar neighbor. Therefore, events occuring on the Sun's surface directly affect us by interfering with satellite operations and communications, astronaut safety, and, in extreme circumstances, power grid stability. Solar flares are a substantial source of hazardous space weather affecting our increasingly technology-dependent society and are the most energetic events in our solar system. Ground-based telescopes have been providing flare observations for over 150 years, but we now live in an era when modern space-bourne observatories provide us with even more stunning visualizations of twisted plasma escaping the Sun's surface. At the same time, these instruments give us the tools necessary to explore the physical mechanisms behind such enormous displays of energy release like never before. With nearly continuous multi-wavelength flare coverage, we can now probe the origins and evolution of flares by tracking particle acceleration, changes in ionized plasma, and the reorganization of magnetic fields. I will present some details behind flare mechanics, particularly magnetic reconnection which is a ubiquitous form of energy release throughout the cosmos, and how they affect the Earth while showing several examples of these truly fantastic explosions.

Subject: Two observational studies using Van Allen Probes data: A case study of an unusually strong, widespread EMIC wave event and its impact on the radiation belts, and a statistical study of low-harmonic m